Agenda/Minutes

Zoom Meeting

CRY+VIS Interface Meeting

Date: 2021/6/18 13:00-

Participants:

Post O3 Upgrade portal

Schedule

• IX: H4 geophone was replaced. Top chamber was closed again.
• IY: Schedule: Rough alignment of TM?
• EX: Adjustment of Yaw FR and IP tuning was finished. Broken cable was recovered. Top chamber was closed.

  • Broken cable

• EY: Assembly of payload is on going. Status of mirror cleaning?

Status

• Corrugate tube fixing jig: Delivery and implement were scheduled on 7/12-13.
• TM height setting: Next target is ITMY.
• Commissioning in air: X-arm.
• Commissioning in vacuum:
• Overall commissioning:
• Acceptance check: Group work is set every Friday.
• PF actuator: After SC.
• Jig for FC painting:
• Separation of rack in 2F: On the maintenance days.
• Disassembly of PRM/PR2 assembly frame: This was scheduled on 6/28-29.

Discussion

VIS Meeting

14:00-

Participants:

Klog

This is generated by python script in /users/Miyo/dropbox/Script/scrapping/main.py.

Summary Report

Type-A

• Tuned the F0 in IY.
• Adjusted the yaw FR in EX. Tuned the IP. The H4 geophone was put on the IP. Repaired some in-vacuum cables.
• Closed the top chambers in IX and EX.

Type-B

Limit switches in SR2 and SR3

There were three switches that didn't seem to be working. Hirata-san fixed them and we checked them with the multimeter. They are working now

SRM

• We measured IP TF on Monday:
  • The resonant frequencies in L and T looked low enough (63 and 55 mHz) so we didn't adjust the ballast masses.
  • The coherence wasn't bad but not excelent either; the frequency resolution was 10 mHz.
• Terrence measured TFs again with a better frequency resolution and found that L and T are highly coupled.

[Terrence]

• Fabian locked the SRM IP so I can measure the LVDT sensor noises.
• I measured the geophone readouts as well when the IP is unlocked. The suspension is quiet enough so these can be used as sensor noise estimates. [notebook sneak peek]
• I then measured transfer functions and cross-transfer functions.

  • cross-coupling is confusing. Explain with figure: klog 17137

  • I reverted the sensing matrix and the actuation matrix using Mark's old matrix, which is derived from geometry.
  • Cross-coupling is still confusing between L and T. But at least I can decouple L2Y, T2Y, Y2L and Y2T.
  • I suspect the lowest frequency modes are L-T coupled. I am pretty sure L and T sensors are not 100% coupled as suggested in the figures.
  • I compared the L and T readout with seismic noise in the x-arm and y-arm direction and L has minimal coherence with x-arm while T has minimal coherence with y-arm.
  • Peaks are too close :*(.
• Some opinion about the RT-model
  • LVDTALIGN and ACCALIGN matrices are great for sensor diagonalization.
  • Why don't add something like COILALIGN (for actuation)?

BS

We revisited the BS IP to check stability and values of resonance frequencies.

• When we adjusted the ballast mass before the temperature 22.7 degrees, this week was 23.5 degrees; O3GK temperature is 23 degrees.

• I moved the IP close to the setpoints using the horizontal fishing rods: it looked unstable, it began moving by small amount but it suddendly moved a lot (e.g. from -1.5 mm to 1.5 mm). With some care I was able to move it at the setpoint and measured TFs, the resonant frequencies were 43 and 86 mHz for L and T respectively.

• We removed 4.5 kg and and the frequencies changed to 93 and 70 mHz for L and T respectively.

• With the same amount of mass we tested different distributions to check whether we can reduce the assymetry between the resonant frequencies in L and T:
  • See klog.

  • The assymetry remains around 25 mHz: one is typically around 65 mHz and the other one around 90 mHz.

  • Becuase of temperature changes one might be too low and the other too high.
  • L and T seem strongly coupled.
• I wonder how to proceed: during installation we were not able to distribute the masses evenly around the circumference becuase the magic wand (yet to be conforimed with a klog entry).

Type-Bp

Type-C

Electronics

Control

Schedule

See Schedule

• Type-A team: ACC preparation
• Type-B team: Remaining work

Milestone

• IMC suspensions are ready in air [40] will finish 2021/04/21.

• PRs are ready in air [643] will finish 2021/07/09.

• ETMX is ready in air [656] will finish 2021/08/25.

• ITMX is ready in air [657] will finish 2021/08/31.

• ETMY is ready in air [658] will finish 2021/09/16.

• ITMY is ready in air [659] will finish 2021/11/08.

• BS is ready in air [691] will finish 2021/11/24.

• SRs are ready in air [663] will finish 2021/12/20.

• Output suspensions are ready in air [695] will finish 2021/12/21.

• TMSY is ready in air [708] will finish 2021/??/??.

• TMSX is ready in air [684] will finish 2021/??/??.

2021/03/29 updated

Safety

Discussion

Travel Plans

The week from 6/21

• Takahashi: 6/21-22
• Hirata: 6/21-22
• Yano: 6/21-25

The week from 6/28

• Takahashi: 6/28-7/2
• Sato: 6/28-7/2
• Hirata: 6/28-7/2
• Yano: 6/28-7/2

Next meeting

• 2021/6/25(FRI)